University of Avignon

About: University of Avignon is a education organization based out in Avignon, Provence-Alpes-Côte-d'Azur, France. It is known for research contribution in the topics: Population & Speaker recognition. The organization has 1526 authors who have published 3766 publications receiving 88928 citations.

A lifetime-based routing protocol for connecting VANETs to the Internet

Abstract: Inter-Vehicle Communications have recently attracted research from both academia and industry. In such networks, vehicles should be able to communicate among each other (V2V) as well as with roadside Infrastructure units (V2I). These units provide some services such as driver information systems and Internet access. Because of the high speed and high mobility of vehicles, establishing and maintaining a connection to these units is very challenging. We introduce a new protocol which uses the characteristics of vehicle movements to predict the vehicle behavior and select a route with the longest life time to connect to the wired network. It aims at spreading the advertisement messages through multi-hops without flooding the network, do seamless hand-overs and select the most stable routes to these units. We performed some simulations and compared the performance of our work with some well-known protocols.

Root age distribution: how does it matter in plant processes? A focus on water uptake

Abstract: Root growth creates a gradient in age at both the scale of the single root, from distal to proximal parts, but also at the root system level when young branch roots emerge from the axis or new nodal roots are emitted that may reach same soil domain as older roots. It is known that a number of root functions will vary with root type and root tissue age (e.g. respiration, exudation, ion uptake, root hydraulic conductance, mucilage release…) and so will the resulting rhizosphere properties. The impact of the distribution of root demography with depth, and related functions, on the overall functioning of the root system is fundamental for an integration of processes at the root system scale. Starting from methods for measuring root demography, we discuss the availability of data related to root age and its spatial distribution, considering plant types (monocot/dicot, perennial/annuals) which may exhibit different patterns. We then give a detailed review of variation of root/rhizosphere properties related to root age, focusing on root water uptake processes. We examine the type of response of certain properties to changes in age and whether a functional relationship can be derived. Integration of changing root properties with age into modelling approaches is shown from 3D models at the single plant scale to approaches at the field scale based on integrated root system age. Functional structural modelling combined with new development in non-invasive imaging of roots show promises for integrating influence of age on root properties, from the local to whole root system scales. However, experimental quantification of these properties, such as hydraulic conductance variation with root age and root types, or impact of mucilage and its degradation products on rhizosphere hydraulic properties, presently lag behind the theoretical developments and increase in computational power.

Synthesis of a Glycolipidic Amphiphilic Nitrone as a New Spin Trap.

Abstract: The synthesis of a new amphiphilic nitrone, A, derived from a digalactosyl tris(hydroxymethyl)aminomethane bearing a perfluorocarbon chain is described. A exhibited a surfactant behavior (cmc = 1.6 × 10-5 mol/L), and the specific recognition of the galactosyl moiety grafted on A by the KbCWL1 membrane lectin was established. Preliminary experiments showed that A was able to trap free radicals in aqueous media, the shape of the observed ESR spectra being strongly dependent upon the nature of the trapped free radical.

Mitochondrial medicine: neuroprotection and life extension by the new amphiphilic nitrone LPBNAH acting as a highly potent antioxidant agent.

Abstract: The search for effective treatments that prevent oxidative stress associated with premature ageing and neurodegenerative diseases is an important area of neurochemical research. As age- and disease-related oxidative stress is frequently associated with mitochondrial dysfunction, amphiphilic antioxidant agents of high stability and selectivity that target these organelles can provide on-site protection. Such an amphiphilic nitrone protected human neuroblastoma cells at low micromolar concentrations against oxidative damage and death induced by exposure to the β-amyloid peptide, hydrogen peroxide and 3-hydroxykynurenine. Daily administration of the antioxidant at a concentration of only 5 μm significantly increased the lifespan of the individually cultured rotifer Philodina acuticornis odiosa Milne. This compound is unique in its exceptional anti-ageing efficacy, being one order of magnitude more potent than any other compound previously tested on rotifers. The nitrone protected these aquatic animals against the lethal toxicity of hydrogen peroxide and doxorubicin and greatly enhanced their survival when co-administered with these oxidotoxins. These findings indicate that amphiphilic antioxidants have a great potential as neuroprotective agents in preventing the death of cells and organisms exposed to enhanced oxidative stress and damage.